/Engine/Plugins/Online/OnlineSubsystemSteam/Source/Public/OnlineSubsystemSteam.h
Whether or not the Steam game server interfaces are available; these interfaces are always available, so long as they were initialized correctly NOTE: The Steam Client does not need to be running for the game server interfaces to initialize NOTE: These interfaces are made unavailable, when not running a server
Whether or not the Steam game server interfaces are available
bool IsSteamServerAvailable()